While there have been some effective HIV prevention interventions developed with young adults, the majority of programs with efficacy for HIV prevention have been developed for adult men who have sex with men (MSM), injection drug users (IDU) and adult heterosexuals. We currently lack (a) culturally appropriate interventions designed specifically for youth, including youth at elevated risk for HIV;and (b) interventions that can effectively reach youth outside our traditional educational system. In this proposal, we endeavor to develop and evaluate an Internet-based social networking program for young adults embedded on MySpace.com, the largest social networking site on the Internet. Youth with participate in every aspect of the design and development of My_Network for Health_Space, resulting in a highly interactive website with culturally appropriate and effective HIV prevention messages that simultaneously take advantage of the youth-oriented culture of technology while capitalizing on the enormous reach of the Internet. We will achieve the following specific aims in this project: 1. Conduct focus groups online at MySpace.com to inform the development of culturally relevant and appropriate social networking pages to promote dialogue about HIV Prevention among youth. 2. Use data from the focus groups to develop My_Network for Health_Space, a site that will be incorporated into the largest online social networking site, MySpace.com. Features of My_Network for Health_Space will likely include (a) peer-to-peer HIV related educational interactive chat rooms, forums, blogs, and testimonial components and (b) an animated weekly serial drama with multiple characters identifying and resolving challenges to HIV prevention over time. 3. Conduct a preliminary social network analysis of youth on MySpace to identify clusters of discrete and dense networks in geographically diverse locations across the U.S. 4. Randomize discrete networks to a trial examining the efficacy of My_Network for Health_Space for maintaining abstinence, increasing condom use, and increasing testing for HIV among participants.